2010-07-22  Richard Guenther  <rguenther@suse.de>

	PR lto/42451
	* gimple.c (gtc_next_dfs_num): New global.
	(struct sccs): Make value a union, add integer same_p member.
	(gtc_visit): New function.
	(gimple_types_compatible_p_1): New function, split out from ...
	(gimple_types_compatible_p): ... here.  Start a DFS walk here.
	(iterative_hash_gimple_type): Adjust for sccs change.

	* gcc.dg/lto/20100720-3_0.c: New testcase.
	* gcc.dg/lto/20100720-3_1.c: Likewise.

From-SVN: r162415